So just to set some context around this. We are trying to work around the limitation of returning only at most 10k results during a search and with filters due to having an immense amount of data and it also coming from multiple indices.
Could I join multiple indices with different fields into one? Sounds like a mess but I figured I'd ask if it's possible.
The second idea is instead of using the child/parent join with the documents if it could be used with two indices. Is this also feasible or is there some other solution.